1. Field of the Invention
The invention disclosed is useful in the manufacture of starting, lighting, and ignition storage batteries such as frequently found in automotive and recreational vehicles.
2. PRIOR ART
In the storage battery industry, there has frequently been recognized the need for a universal battery container having standard outside dimensions and internal flexibility which would permit varying electrical capacity. The industry in the past has met the need for varying electrical capacity by altering the number of negative and positive plates which are used to make up the elements of each cell of the battery. The number of cells which a particular battery container has is then cell multiple of the nominal voltage of the elements. Within a given battery size, there are a variety of electrical capacities available. In the higher capacity batteries the number of battery plates which make up the elements are greater per element. Conversely, the number of battery plates in element for a smaller capacity battery is less. Since the external dimensions of the batteries within a particular size class is standard within the industry, the battery manufacturer must adjust the cell area to receive either the thicker battery elements containing a larger number of plates or the thinner elements containing the lesser number of plates.
In the past this has been achieved in two ways. The first approach was to mold individual containers having different cell areas. The cell areas were modified by increasing or decreasing the size of a plurality of ribs disposed along the walls defining the cell. In this way a larger rib would be used for the smaller battery element and a smaller rib would permit accommodate of a larger battery element. A second approach was to add additional spacer members between the battery plates of a given element so that an element having lesser plates would be filled or expanded by the use of separators as sham plates.
A more recent development has been the use of a single battery container within a size classification which is modified to accommodate larger elements. The universal battery container has ribs which are molded to accommodate the smallest or thinnest element within a size classification. When it is desired to use the battery container for a battery having a larger electrical capacity and therefore thicker battery elements the ribs of the battery container are trimmed with a mechanical device to remove a portion of the rib and therefore open the volume of the cell. This technique while in advance over the prior art technique of using additional separators, still presents the problem of sophisticated mechanical equipment necessary to perform the trimming and the associated problem of removing the trimmings from the battery container.
The instant invention seeks to solve the problem of a universal battery container as well as the problems associated with trimming and scrap removal by providing an apparatus for thermally modifying the between the rib space in the cell. The apparatus may be used to modify the between the rib space in a single operation and does not require the removal of scrap from the battery container.